Midway 2.0 Unveiled: Key Features and Performance Boosts for Node.js Developers

New Features

Midway 2.0 replaces the compiler‑based Hook implementation with a runtime solution using Node.js AsyncLocalStorage, eliminating startup latency, syntax limits, and TypeScript compatibility issues while unlocking new possibilities.

1. Reduced Syntax Restrictions

Version 1.0 required strict naming and calling conventions for Hooks, burdening developers. In 2.0 these constraints are removed; Hooks can be used in any function without naming limits.

Example code that now runs:

export async function get () {
  return { type: 'GET' };
}
export async function post (message: string) {
  return { type: 'POST', message };
}

We still recommend naming Hook functions with the use prefix for clarity.

2. Code Reuse

Hooks can now be packaged as reusable npm modules, allowing shared libraries across projects.

3. Ultra‑Fast Startup

Version 1.0 performed heavy compilation at launch, causing start times >10 seconds for new projects. Midway 2.0’s pure runtime approach reduces cold start and restart to under 2 seconds, regardless of file count.

The runtime no longer creates .faas_debug_tmp cache folders, keeping project directories tidy.

Unit Testing

Midway Hooks now support two testing APIs: runFunction for pure function testing and request for full HTTP testing.

import { createApp } from '@midwayjs/hooks-testing-library';
import { get, post } from './api';

it('GET', async () => {
  const app = await createApp();
  expect(await app.runFunction(get)).toEqual({ type: 'GET' });
  expect(await app.runFunction(post, '2.0')).toEqual({ type: 'POST', message: '2.0' });
});

import { createApp } from '@midwayjs/hooks-testing-library';
import { get, post } from './api';

it('GET', async () => {
  const app = await createApp();
  const response = await app.request(get);
  expect(response.status).toEqual(200);
  expect(response.type).toEqual('application/json');
  const postResponse = await app.request(post, '2.0');
  expect(postResponse.status).toEqual(200);
  expect(postResponse.type).toEqual('application/json');
});

Plugin‑Based and Functional Configuration

In 1.0, Hooks were tied to the faas-cli plugin. In 2.0 they become a first‑class Midway component, usable in any Midway project, whether serverless or traditional web.

import { hooks, createConfiguration } from '@midwayjs/hooks';
import logger from './logger';

export default createConfiguration({
  imports: [
    hooks({
      middleware: [logger],
    }),
  ],
});

Hooks Middleware

Midway 2.0 adds three middleware scopes: global, file‑level, and function‑level (compatible with 1.0).

import { Context } from '@midwayjs/faas';
import { useContext } from '@midwayjs/hooks';

const logger = async (next: any) => {
  const ctx = useContext<Context>();
  console.log(`<-- [${ctx.method}] ${ctx.url}`);
  const start = Date.now();
  await next();
  const cost = Date.now() - start;
  console.log(`[${ctx.method}] ${ctx.url} ${cost}ms`);
};

import { ApiConfig } from '@midwayjs/hooks';
import logger from './logger';

export const config: ApiConfig = {
  middleware: [logger],
};

export default async (message: string) => {
  return { type: 'POST', message };
};

Project Configuration

Midway 2.0 introduces midway.config.ts to replace the limited f.yml. Developers can define source directories, routes, and devServer options via defineConfig.

import { defineConfig } from '@midwayjs/hooks';

export default defineConfig({
  source: 'src/apis',
  routes: [
    { baseDir: 'lambda', basePath: '/api' },
  ],
});

File routing is now unified under this config, with defaults of /src/apis (customizable) and support for pure API projects ( /src).

DevServer can ignore specific patterns, e.g., static assets.

Multi‑Scenario Support

Midway 2.0 supports pure API projects, web server deployments (using Koa as the underlying framework), and integrates with popular tools like Vite and Prisma.

Example of adding a Koa body parser globally:

import { hooks, createConfiguration } from '@midwayjs/hooks';
import bodyParser from 'koa-bodyparser';

export default createConfiguration({
  imports: [
    hooks({
      middleware: [bodyParser()],
    }),
  ],
});

When running on a web server, useContext provides a Koa Context object.

import { useContext } from '@midwayjs/hooks';
import { Context } from '@midwayjs/koa';

function useKoaContext() {
  return useContext<Context>();
}

export default async () => {
  return {
    message: 'Hello World',
    method: useKoaContext().method,
  };
};

Open‑Source Ecosystem

Midway 2.0 is fully open source (https://github.com/midwayjs/midway) and embraces modern tooling such as Vite for fast front‑end builds and Prisma for type‑safe database access.